Brake tester



March 15, 1932. E* L. H CURRA 1,849,910

BRAKE TESTER Filed May 5. 1930 'i INVENoR. 175119- A ELJI. Umb/an ATTORNEY. l

Patented Mar. 15, 1932 EUGENIE IBI. CURRAN, OF PORTLAND, OREGON BRAKE TESTER Application led May 5, 1930. Serial No. 449,988.

This invention relates to a brake tester and has for its primary object toprovide, in a manner as hereinafter set forth, a device for successive application to the brake carrying wheels of a motor vehicle to determine the pressure required to turn each wheel against the action of its'brake, thereby enabling the brakes to be accurately adjusted for even operation and maximum eiiiciency.

A further object of the invention is to provide a brake tester as aforesaid which includes a pair of reciproc'able tire clamps mounted on a common screw, and which further includes a spring resisted, slidable rod for coaction with a scale to indicate the pressure necessary to turn the wheel upon which the test is being made. v v

With the foregoing and other objects in view, the invention consists of the novel con-` struction, combination and arrangement of parts as hereinafter more particularly described, and as illustrated in the accompanying drawings wherein is shown an embodii ment of the invention, `but it is to be understood that the description and drawings are to be taken as illustrative and that the linvention is intended to be limited only by the scope of the claims hereunto appended.

In the accompanying drawings in which like numerals are employed to designate like parts throughout the several views 4Figure 1 is an elevation of a vehicle wheel showing an embodiment of my invention in ,A association therewith.v

Figure 2 is an enlarged section taken on the line 2-f-2 of Figure 1.

Figure 3 is an enlarged section taken on the line 3 3 of Figure 1.

Figure 4 is a perspective view of a modified form of support for the tire clamps.

Figure 5 is a perspective View of a closure block for one end of the support shown in Figure 4.

Figure 6 is a perspective view of one ofthe 5 clamps used in connection with the support shown in Figure 4.

Figure 7 is an elevation of the casing for the pressure indicator.

Referring to the drawings in detail, the numeral 1 indicates generally a vehicle wheel including a tire 2 and a brake 3. Adapted to engage the tire 2 on opposite sides thereof are a pair of oppositely disposed, arcuate clamps 4 f which extend through longitudinally aligned slots 5 in va cylindrical supporting member 6, and which are formed with` cylindrical bases 7 disposed within the supporting member 6. The bases 7 are internally threaded and are mounted on right and left hand threaded portions 8 and 9 respectively of a screw 10 disposed within the-supporting member 6. rlhe supporting member 6 is provided at one end with a closure block 11 which is secured in position by means of a plurality of holdfast devices 12. The block 11 is formed with a centrally disposed opening 13 through which the screw 10 rotatably extends, the screw 10 having a smooth face portion 14 projecting from the outer face of the bloclell. The inner end of the smooth face portion 14 is provided with a circumferentially extending groove 15 for engagement by a set screw 16` carried by the block 11 to prevent longitudinal movement of the screw relative to the supporting member when the screw is rotated. y Y

Secured to the end portion 14 of the screw, by means of a suitable pin 17, is a head block 18 which is formed with a socket 19 extending at a right angle to the plane of the screw 10. The outer end portion of the socket 19 is internally threadedand has secured therein the externally threaded open end of a cylindrical casing 20 having its opposite end closed. Extending through the bottom wall of the socket 19 and into the casing 20 is a slidable rod 21, which is provided adjacent its inner end with a cross pin 22, the ends of which proj ect through longitudinally extend-y ing, diametrically opposed slots 23 formed ou in the casing 20. Encircling the rod 21 is a coiled spring 24, the respective ends of which abut against the cross pin 22 and the bottom wall of the socket 19.v Encircling the casing 20 and seating on end portions nof the cross pin 22 is an annulus 25 which is adapted to be moved across the calibrated outer face 26 of the casing. VThe rod 21 is provided at its outer end with a handle member 27.V p

When applying the-brake tester to a wheel, 100

the latter is jacked up as shown in Figure 1,

and the supporting member 6 is placed transverselyv of the tire 2 with the clamps 4 disposed on opposite sides of the tire. The head block 18 is then rotated by means of the rod 21 which causes a rotation of the screw 10, and owing to the right and left hand threads of the screw in engagement with the bases 7 of the clamps 4, the latter will be moved toward each other to firmly grip the tire on opposite sides thereofl Witlr the clamps irmly gripping the tire, an outward pull is exerted on the rod 21 against the tensiionof the spring 24 until the wheel is `turned against the gripping action of its'brake which is set thereagainst. Prior to the turningl of the wheel, the rod 21y will be moved. longitudinally of the casing 20 whereby the annulus 25 will` be drawn across the calibrations 26- on the outer face ofthe casing. Upon the turningof. the wheel the rod 21 is released and the crosspin 22 will be returnedtol its position adjacent the closedend of the casing by the action of the spring 24.. The positi-on of the annulus 25 may then be read in connection with the calibrations 26y to determine the amount ofY pressure which Wasrequired to turn* the wheel against its brake; y

If desired a supporting member such as28' shown in Figure 4f may ber substitutedfor theV supportingy member 6, and a pair of clamps such. as. 29 shown inv Figure 6 substituted for the clamps L1. The supporting member 21S-,is

of hollow construction rectangular` in' cross section and is;formedl in one wall' with Ya slot 30 extending; throughout its. entire length.

' Each ofthe clamps29 is formed with a base.

31:, of rectangular formation which fits: Withingtheifhollow interiorof the supporting vmem-- ber 28. Owing'to the rectangular formation. of the bases 31 and the hollow interior ofthe;

supportingmember 28, the pressure on; the supporting member during theeturning of-the wheelis distributed over am entire sidewall' of: the supporting' member whereby a; mini;-

mum; of pressure; isconcentrated on. a side'A wa'lliofthe' slot 30.4

Itris.4 thought that the many advantages of:

agbrakestesterin accordance with this inten-- iiibn. will be'I readily apparent, and although;

the.` preferred: embodiment of the-invention isaszillustrateid; and described, itis tobef. understood that ohangesin. the size, shape and aarran-gement of parts'. may be resortedk to, so

long asf such: changes falla within thescopeA ofiv into-the casing,l

for coaction` with the calibrated faceioffthe,

, and being movable longitudinally of the latcasing, an indicating element for coaction with the calibrated face of the casing, and

Amea'nsoperatively connecting said indicating .element to saidrod.

2. A brake" tester comprising, a hollow supporting member adapted. to be4 placed .transversely of a vehicle wheeltire,I said member having a longitudinal slot, a.' pair of.' opposite-ly disposed clamps on opposite sides.. off.' they tire,l said clamps healingV internally threaded bases disposed withinthe support-y member and being movabley longitudi-V.

nally of the latter,.a screw having. right and left hand threaded portionsfrespectively en.- gaging the threaded,basesY ofthe clamps., a rotatable head block iixedly secured to. one end-.of the screw, a casing carried by thehead block and extending at a. right. angleto the longitudinal plane, of the screw, said casing having a calibrated outer face, a springgre.- sisted, Slidable rodA extending through the head block and into the casing, an indicating element for coaction. with: thecalibrated face of. the-casing,.and means operatively connecting said indicating elementtolsaid rod-7, said clamps being of'arcuate formation;

3. A brake tester comprising,.a hollow sup.- portingy member adapted to be placed. trans.- versely` of a. vehicle wheel tire, said. member having a longitudinal slot, pa-ir ofoppo.-` sitely disposed clamps ron; opposite sides ofV the tire,.saidfclampshaving internally thread.- edbases disposed within the supportingmember and. being movable. longitudinally of the latter, a screw having right and left'jhand.v

threaded" portions respectively engaging the threaded bases of the clamps a rotatable4 headblock ixe'dly securedf'tofone end ofthe. screw, a casingcarried'byl thehead'blogcli and extending at a right angle to the longitudinal plane ofthe screw, said' casingl having a Vcali.-`V

brated outer face, a spring resisted`slidable rod extending through, the: head block and. andan indicating element casing, said indicating element being openatively connected. with said nodto move/therewith, said casing having apair OflOngitudinally extending, diametrically opposed sl'ots, saidV rod'having a. crOSspineXtending through said slots, said indicating element encircling said casing and seatingon saidk cross pin..

4. A brake tester comprising, a hollowv sup-- porting member adapted toA be. placed! transversely of a vehicle'wheel. tir,e,said mem-ber 130 having a longitudinal slot, a pair of oppositely disposed clam s on opposite sides of the tire, said clamps aving internally threaded bases disposed within the supporting member and being movable longitudinally of the latter, a screw having right and left hand threaded portions respectively engaging the threaded bases of the clamps, a rotatable head block iixedly secured to one end of the screw, a casing carried by the head block and extending at a right angle to the longitudinal plane of the screw, said casing having a calibrated outer face, a spring resisted, slidable rod extending through the ead block and into the casing, an indicating element for coaction with the calibrated face of the casing, and means operatively connecting said indicating element to said rod, said casing having an externally threaded open end, said head block being formed with a socket having a threaded wall portion engaging the ex ternally threaded end of the casing.

5. A. brake tester comprising, a hollow supporting member adapted to be placed transversely of a vehicle wheel tire, said member having a longitudinal slot, a pair of oppositely disposed, arcuate clamps on opposite sides of the tire, said clamps having internally threaded bases disposed within the supporting member and being movable longitudinally of the latter, a screw having right and left hand threaded portions respectively engaging the threaded bases of the clamps, a closure block fixedly secured to one end of the supporting member and having a centrally disposed opening, said screw having a smooth faced end portion extending through the opening in the closure block, a rotatable head block ixedly secured to the smooth faced end portion of the screw, a casing carried by the head block and extending at a right angle to the longitudinal plane of the screw, said casing having a calibrated outer face, a spring resisted, slidable rod extending through the head block and into the casing, an indicating element for coaction with the calibrated face of the casing, and means operatively connecting said indicating element to said rod.

6. A brake tester comprising, a hollow supporting member adapted to be placed transversely of a vehicle wheel tire, said member having a longitudinal slot, a pair of oppositely disposed, arcuate clamps on opposite sides of the tire, said clamps having internally threaded bases disposed within lthe supporting member and being movable longitudinally of the latter, al screw having right and left hand threaded portions respectively engaging the threaded bases of the clamps, a closure block ixedly secured to one end of the supporting member and having a centrally disposed opening, said screw having a smooth faced end portion extending through the opening in the closure block,

a rotatable head block xedly secured to the smooth faced end portion of the screw, a casing carried by the head block and extending at a right angle to the longitudinal plane of the screw, said casing having a calibrated outer face, a spring resisted, slidable rod eX- tending through the head block and into the casing, an indicating element for coaction with the calibrated face of the casing, and means operatively connecting said indicating element to said rod, said smooth faced end portion of the screw being provided with a circumferentially extending groove, said closure block having a set screw engaging the walls of said groove to prevent longitudinal movement of the screw relative to the4 supporting member when the screw is rotated.

7. A brake tester comprising, a hollow supporting member adapted to be placed transversely of a vehicle wheel tire, said member having a longitudinal slot, a pair of oppositely disposed clamps on opposite sides of the tire, said clamps having internally threaded bases disposed within the support-ing member and being movable longitudinally of the latter, a screw having right and left hand threaded portions respectively engaging the threaded b-ases of the clamps, a casing extending transversely of the longitudinal plane of the screw, means rigidly connecting the casing with the screw, said casing having a calibrated outer face, a slidable rod extending into the casing, means yieldably resisting movement of the rod longitudinally of theV casing, an indicating element for coaction with the calibrated face of the casing, and means operatively connecting said indicating element to said rod.

In testimony whereof, I affix my signature hereto.

EUGENIE L. I-I. CURRAN. 

